Some of us like to get more boost and performance out of our stock turbos instead of upgrading to a new one and the Turbosmart actuator does just that. This will allow you to push the turbo harder and make it more reactive to boost control input to get more performance out of your turbo. Typically, spool time can be increased as well as higher top end boost holding capability. A much nicer looking actuator as well, it's made of billet aluminum and anodized black.
Stock wastegate didn't hold boost. I pressurized it under water and there was alot of bubbles. Turbosmart wastegate no bubbles!